A USIM refers to a single module, which includes a Subscriber Identity Module (SIM) card loaded with subscriber information and a Universal Integrated Circuit Card (UICC) are combined with each other, and has various functions, such as user authentication, global roaming, electronic commerce, etc. While a SIM stores personal information in order to provide various services, such as authentication, the charging of price, and security function, to subscribers of a mobile communication service, the USIM has both a subscriber authentication function one-step evolved from the subscriber authentication function of the SIM and the functions of a Universal IC Card (UICC), such as a transportation card, a credit card, etc.
Meanwhile, a USIM unlock environment signifies an environment where a USIM having information on a mobile communication subscriber can be moved between and used for multiple terminals. In the USIM unlock environment, by carrying the USIM, it is possible to use a voice mobile phone service, including international roaming, and an electronic commerce service, regardless of the types of terminals and communication providers.
Meanwhile, in association with Digital Multimedia Broadcasting (DMB), active research has recently been conducted in order to integrate a broadcast receiving function into a mobile communication terminal, so that an infrastructure has been recently constructed, in which it is possible to view a DMB broadcast upon receiving the DMB broadcast with the configuration of a terrestrial DMB receiving unit or a satellite DMB receiving unit in a mobile communication terminal.
In the case of viewing a DMB broadcast by using a mobile communication terminal, not only the viewer information but also information on the terminal, i.e. terminal information provided from a USIM card or a SIM card, is necessary. That is, since not only personal information on a viewer but also terminal information is required in order to view a DMB broadcast, each of recently produced terminals is equipped with a USIM card or a SIM card.
Also, a broadcast receiving chip is mounted within the terminal. The broadcast receiving chip may have various forms, such as a Subscriber Identity Module (SIM), a Surface Mounted Device (SMD), a Multiple Chip Package (MCP), and the like. The broadcasting chip as described above is usually a HardWare (H/W) module loaded with broadcast subscriber information, which has a stable structure. Differently from the USIM, the broadcasting chip is usually fixedly embedded in a terminal, and restricts broadcast reception by exchanging a broadcast recipient's personal information with a broadcasting system, e.g., a broadcast conditional access system.
In a broadcasting system, satellite DMB from among various DMB services restricts broadcast reception such that only paying subscribers can receive a relevant broadcast, like other types of satellite broadcasting services. Such a system as described above in which only subscribers can selectively receive broadcasts is called a Conditional Access System (CAS) and is applied to the satellite DMB.
Representative examples of receivers, to which the CAS is applied, include a set-top box for receiving pay channels of satellite broadcasting or cable broadcasting. Generally, a broadcast to which the CAS is applied, is sent in a state where images, sounds, and the like of the broadcast have been scrambled according to a prescribed algorithm or processed according to other schemes so that it is impossible to view the broadcast by itself. Then, the scrambled broadcast information can be restored to its original state by analyzing the relevant algorithm through the set-top box, thereby enabling normal viewing of the broadcast. Therefore, only subscribers are allowed to view the relevant broadcast. Hence, in the case of satellite DMB where subscriber-based broadcasting is considered, even a mobile communication terminal equipped with a DMB receiving unit for receiving a DMB broadcast requires a means for supporting the CAS.
The abovementioned CAS corresponds to such a system that a user's receiver determines if it is possible to receive a particular broadcast program. The CAS is intended to allow only those who pay a legitimate receiving fee to view programs, and viewing of digital broadcasting can become charged through the CAS. On this account, it can be said that the CAS is an element essential to commercialize digital broadcasting. The CAS having a conditional access function (or the reception restriction function) is configured to include scrambling technology of mixing voice data, image data, and the like for the protection from an unauthenticated reception, encryption technology of delivering data by using a control word key so as to view a broadcast only with a specific receiver, and the user service support function of providing users with various forms of services based on the scrambling technology and the encryption technology. A conventional CAS employs a fixed-type disc descrambler device in which a decoding algorithm and secret keys are stored, but recently, it is generalized to deliver, by a smart card loaded with unique personal information of a subscriber, a secret key to a user in consideration of the charging of price, convenience property, security, and others.
As illustrated in FIG. 1, the CAS as described above includes: an Entitlement Control Message (ECM) generator for generating an ECM upon receiving program information, package information, etc., from a TCS (i.e., a broadcast schedule generator); an Entitlement Management Message (EMM) generator for generating an EMM upon receiving subscriber information and purchase information from an SCIS (i.e., a subscriber management system); and a security/authentication server for carrying out encryption with the application of a reliable security algorithm so as to safely deliver a control word.
Also, the CAS is assigned a digital signature which authenticates a message, such as an ECM, an EMM, etc., as a legal message sent from a broadcasting center and can then confirm the transformation of a relevant message, and includes receiver CA SoftWare (S/W) equipped within a receiver, which takes charge of authentication and filtering in regard to a message, such as an ECM, an EMM and the like, and carries out a mutual authentication between a smart card and a receiver. In addition, the above smart card corresponds to a card having a built-in chip equipped with its own processor and memory, which is provided to a subscriber so as to view satellite broadcasting, and both physical and electrical characteristics and a transfer protocol of the smart card comply with a definition of ISO 7816-1, 2, and 3.
Therefore, the CAS receives an input ECM from a receiver, and then makes a comparison between conditional access properties (i.e., a viewing right, reception area restriction, reception age restriction, etc.) of the ECM and the contents of the smart card, thereby determining if a broadcast can be received. If it is determined that a broadcast can be received, the CAS generates a control word corresponding to a key capable of descrambling a scrambled broadcasting signal to provide the generated control word to the receiver, and performs a command delivered by the EMM, thereby modifying or producing information (i.e., subscriber information, purchase information, etc.) within the smart card.
Along with the SCIS, the CAS so configured as described above corresponds to a core system of a broadcasting system required for a pay digital satellite broadcasting service, enables each subscriber to be provided with desired services in an accurate and convenient manner, prevents illegal viewing for the sake of broadcasters, and provides various marketing data, such as each subscriber's viewing propensity and others, thereby providing a system which enables a viewer-oriented broadcasting service on the basis of the various marketing data.
However, the CAS as described above is used as a system for restricting broadcast reception. Therefore, in the case of DMB-receiving mobile terminals that have recently been widely used, replacement of a terminal device may restrict reception of broadcast programs, which causes inconvenience in the use of the mobile terminal. That is, since it is usual that a broadcasting chip is fixed to a terminal differently from a USIM, a broadcasting chip of the new terminal cannot be replaced by a broadcasting chip of an existing terminal even when the existing terminal is replaced by the new terminal and a USIM of the existing terminal is mounted in the new terminal. Then, the CAS cannot recognize correlation between recipient information and the new terminal, and cannot provide proper control to the pay digital satellite broadcasting service.